Shoreline Processes near Barrow, Alaska: A Comparison of the Normal and the Catastrophic

• Published in: ARCTIC
• Main Authors: Hume, James D., Schalk, Marshall
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Arctic Institute of North America 1967
• Subjects: Atmospheric pressure; Beaches; Breakup; Climate change; Coast changes; Coasts; Diurnal variations; Erosion; Floods; Formation; Gravel; Ice cover; Sea level; Seasonal variations; Sediment transport; Storms; Tides; Winds; Velocity; Barrow region; Alaska; Barrow waters; Barrow; Point; region; waters; Tempêtes; Arctic; Point Barrow; Sea ice
• Online Access: https://journalhosting.ucalgary.ca/index.php/arctic/article/view/66336

The normal average yearly net transport of sediment along the Alaska coast west of Pt Barrow to the NE is 10,000 yd³, to the east of Barrow, 9,500 yd³. An Oct 1963 storm with gusts of up to 75 mi/hr, over an ice-free ocean, produced 10-ft waves and a storm surge of 11-12 ft; it moved >200,000 yd³ sediment, caused coastal flooding and >$3 million damage. If climate is warming, such storms can be expected more frequently. The normal daily tide at Barrow is about 6 in (except in storm) and an additional monthly variation of about 5 in. Storm tides of several feet are caused by rise of sea level under a low pressure area and by onshore wind. Ice damps waves and wave-generated currents. Freeze-up occurs 2 Sept- 19 Dec, breakup 17-23 July. Even when considered open and navigable, the water may have scattered ice near Barrow and sea ice a few mi offshore, which would act as a damper of waves. The northern Alaska coast is one of transgression, with the recent dominant action of coastal submergence. The gravel along beaches cannot be replaced by natural processes without a large amount of erosion. It should be left in place as protection. Évolution du rivage près de Barrow, Alaska: comparaison entre le normal et le catastrophique. Entre 1948 et 1952, des études sur le mouvement des sédiments le long de la côte de l'Alaska, à l'ouest de Point Barrow, ont indiqué un transport annuel moyen normal vers le nord-est de 10,000 yards cubes (7645 m³). Des études analogues entreprises en 1958 indiquaient un mouvement vers le sud-est de 9,500 yards cubes (7263 m³).Le 3 octobre 1963, une tempête, accompagnée de rafales atteignant 75 milles à l'heure (120 kmh) souffla sur l'océan libre de glace et vint frapper la côte. Des vagues estimées à 10 pieds (2,05 m), renforcées d'une vague de fond causée par la tempête et haute de 11 à 12 pieds (3,35-3,65 m), inondèrent les régions côtières et causèrent pour plus de millions de dollars de dégâts. Cette tempête – probablement une tempête de "deux siècles" – déplaça plus de 200,000 yards cubes (152,900 m³) de sédiments, soit le transport normal de vingt années. Si le climat est véritablement en train de se réchauffer, il faut s'attendre à ce que de telles tempêtes se produisent plus fréquemment. Les constructions voisines de la côte devront donc être prévues en conséquence.